package com.njuzr.eaibackend.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.njuzr.eaibackend.dto.AiSpeakingAssignmentDTO;
import com.njuzr.eaibackend.enums.AssignmentStatus;
import com.njuzr.eaibackend.enums.Role;
import com.njuzr.eaibackend.exception.MyException;
import com.njuzr.eaibackend.mapper.*;
import com.njuzr.eaibackend.po.*;
import com.njuzr.eaibackend.service.AiSpeakingAssignmentService;
import com.njuzr.eaibackend.utils.ConvertUtil;
import com.njuzr.eaibackend.vo.AiSpeakingAssignmentVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.*;

/**
 * @author Liululin
 * @date 2025/3/18 - 14:53
 */
@Service
@Slf4j
public class AiSpeakingAssignmentServiceImpl extends ServiceImpl<AiSpeakingAssignmentMapper, AiSpeakingAssignment>  implements AiSpeakingAssignmentService {
    @Autowired
    CourseMapper courseMapper;
    @Autowired
    AssignmentMapper assignmentMapper;

    @Autowired
    UserMapper userMapper;

    @Autowired
    StudentAssignmentMapper studentAssignmentMapper;
    @Override
    public void createSpeakingAssignment(MyUserDetails user, Long courseId, AiSpeakingAssignmentDTO aiSpeakingAssignmentDTO) {
        Course course = courseMapper.selectById(courseId);
        if (course == null)
            throw MyException.create(HttpStatus.BAD_REQUEST, "课程不存在");
        if (user.getRole() != Role.ADMIN) {
            List<String> teacherIds = Collections.singletonList(Optional.ofNullable(course.getTeacherIds())
                    .orElse(Collections.emptyList().toString()));
            String userIdStr = String.valueOf(user.getId());
            boolean hasTeacherId = teacherIds.contains(userIdStr);
            boolean pidMatches = Objects.equals(course.getTeacherPid(), user.getPid());
            if (!hasTeacherId && !pidMatches) {
                throw MyException.create(HttpStatus.BAD_REQUEST, "无权限创建");
            }
        }

        Assignment assignment = new Assignment();
        BeanUtils.copyProperties(aiSpeakingAssignmentDTO, assignment);
        assignment.setCourseId(courseId);
        assignment.setTeacherId(user.getId());
        assignment.setCreateTime(new Date());
        try {
            assignmentMapper.insert(assignment);
            Long assignmentId = assignment.getAssignmentId();
            log.info("assignmentId:" + assignmentId);
            AiSpeakingAssignment aiSpeakingAssignment = new AiSpeakingAssignment();
            aiSpeakingAssignment.setAssignmentId(assignmentId);
            BeanUtils.copyProperties(aiSpeakingAssignmentDTO, aiSpeakingAssignment);
            if(aiSpeakingAssignmentDTO.getSurveyLinks() != null){
                aiSpeakingAssignment.setSurveyLinks(ConvertUtil.listToString(aiSpeakingAssignmentDTO.getSurveyLinks()));
            }
            baseMapper.insert(aiSpeakingAssignment);
        } catch (Exception e) {
            log.error(e.getMessage());
            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "创建作业失败");
        }
    }

    @Override
    public AiSpeakingAssignmentVO findAssignmentById(Long assignmentId) {
        QueryWrapper<Assignment> wrapper = new QueryWrapper<>();
        wrapper.eq("assignment_id", assignmentId);
        Assignment assignment = assignmentMapper.selectOne(wrapper);
        if (assignment == null)
            throw MyException.create(HttpStatus.BAD_REQUEST, "作业不存在");
        QueryWrapper<AiSpeakingAssignment> speakingAssignmentQueryWrapper = new QueryWrapper<>();
        speakingAssignmentQueryWrapper.eq("assignment_id", assignmentId);
        AiSpeakingAssignment aiSpeakingAssignment = baseMapper.selectOne(speakingAssignmentQueryWrapper);
        return convertToVO(assignment, aiSpeakingAssignment);
    }

    private AiSpeakingAssignmentVO convertToVO(Assignment assignment, AiSpeakingAssignment aiSpeakingAssignment) {
        AiSpeakingAssignmentVO aiSpeakingAssignmentVO = new AiSpeakingAssignmentVO();
        BeanUtils.copyProperties(assignment, aiSpeakingAssignmentVO);
        BeanUtils.copyProperties(aiSpeakingAssignment, aiSpeakingAssignmentVO);
        if(aiSpeakingAssignment.getSurveyLinks() != null){
            aiSpeakingAssignmentVO.setSurveyLinks(ConvertUtil.stringToList(aiSpeakingAssignment.getSurveyLinks(), String::valueOf));
        }
        aiSpeakingAssignmentVO.setStatus(calculateStatus(aiSpeakingAssignmentVO.getStartTime(), aiSpeakingAssignmentVO.getEndTime()));
        // 组装老师姓名
        aiSpeakingAssignmentVO.setTeacherName(userMapper.selectNameById(assignment.getTeacherId()));
        return aiSpeakingAssignmentVO;
    }

    @Override
    @Transactional
    public boolean updateAssignment(MyUserDetails user, Long assignmentId, AiSpeakingAssignmentDTO aiSpeakingAssignmentDTO) {
        Assignment assignment = assignmentMapper.selectById(assignmentId);
        if (!Objects.equals(assignment.getTeacherId(), user.getId()))
            throw MyException.create(HttpStatus.BAD_REQUEST, "无权限更新");
        Assignment newAssignment = new Assignment();
        BeanUtils.copyProperties(aiSpeakingAssignmentDTO, newAssignment);
        newAssignment.setAssignmentId(assignmentId);
        AiSpeakingAssignment aiSpeakingAssignment = new AiSpeakingAssignment();
        BeanUtils.copyProperties(aiSpeakingAssignmentDTO, aiSpeakingAssignment);
        aiSpeakingAssignment.setAssignmentId(assignmentId);
        if(aiSpeakingAssignmentDTO.getSurveyLinks() != null){
            aiSpeakingAssignment.setSurveyLinks(ConvertUtil.listToString(aiSpeakingAssignmentDTO.getSurveyLinks()));
        }
        try {
            int code1 =  assignmentMapper.updateById(newAssignment);
            UpdateWrapper<AiSpeakingAssignment> updateWrapper = new UpdateWrapper<>();
            updateWrapper.eq("assignment_id",assignmentId);
            int code2 = baseMapper.update(aiSpeakingAssignment, updateWrapper);
            if ((code1 | code2) == 0)
                throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "服务器更新失败");
        } catch (Exception e) {
            log.error(e.getMessage());
            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "服务器更新失败");
        }
        return true;
    }

    @Override
    @Transactional
    @CacheEvict(value = "assignmentInfo", key = "'assignment_' + #assignmentId")
    public void deleteById(Long teacherId, Long assignmentId) {
        Assignment target = assignmentMapper.selectById(assignmentId);
        if (!Objects.equals(target.getTeacherId(), teacherId))
            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "无权限删除");

        try {
            List<Engagement> engagements = studentAssignmentMapper.findEngagementByAssignmentId(assignmentId);
            for(Engagement engagement : engagements) {
                studentAssignmentMapper.delete(engagement.getStudentId(), assignmentId);
            }
            int code = assignmentMapper.deleteById(assignmentId);
            QueryWrapper<AiSpeakingAssignment> speakingAssignmentQueryWrapper = new QueryWrapper<>();
            speakingAssignmentQueryWrapper.eq("assignment_id", assignmentId);
            int code1 = baseMapper.delete(speakingAssignmentQueryWrapper);
            if (code==0 || code1 == 0) {
                throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "删除作业错误");
            }
        } catch (Exception e) {
            log.error(e.getMessage());
            throw MyException.create(HttpStatus.INTERNAL_SERVER_ERROR, "删除作业错误");
        }

    }

    private AssignmentStatus calculateStatus(Date startTime, Date endTime) {
        Date now = new Date();
        if (now.before(startTime)) {
            return AssignmentStatus.NOT_STARTED;
        } else if (now.after(endTime)) {
            return AssignmentStatus.FINISHED;
        } else {
            return AssignmentStatus.PROCEEDING;
        }
    }
}